#include<stdio.h>
#include<string.h>
#define N 80
char* reserve_stract(char* dest, char* src)
{
	char* ret = dest;
	char* rets = src;
	while (*dest != '\0')
	{
		dest++;
	}
	while (*src!='\0')
	{
		src++;
	}
	src--;
	do {
		*dest = *src;
		src--;
		dest++;
	} while (src >=rets);
	*dest = '\0';
	return ret;
}
int main()
{
	char dest[N] = "hello";
	char src[] = "world";
	printf("%s", reserve_stract(dest, src));
	return 0;
}